Medicare Part D Open Enrollment runs from October 15 to December 7 each year

Medicare Part D open enrollment is a fixed window every fall when you can join, switch, or drop a prescription drug plan. The dates are the same each year: October 15 through December 7. Any changes you make during this period take effect on January 1 of the following year.

This is different from the general Medicare enrollment period (which runs January 1 to March 31) and from Special Enrollment Periods, which open if you have a may have access to life event like losing employer coverage or moving to a new state. Part D open enrollment happens once annually, and missing the window means you cannot change plans until the next October — unless a may have access to event occurs.

If you are already enrolled in a Part D plan and do nothing during open enrollment, your current plan continues into the new year. However, plans change their formularies (the drugs they cover), premiums, and copays every January, so reviewing your coverage each fall is important even if you plan to stay with your current plan.

Key Takeaways

  • Medicare Part D open enrollment is October 15 to December 7 each year, and changes take effect January 1.
  • You can join a plan for the first time, switch to a different plan, or drop your current plan during this window.
  • If you miss the important date and do not have a may have access to event, you cannot change plans until the next October.
  • Your current plan's costs and drug coverage will change on January 1, so comparing plans during open enrollment can save you money.
  • You can compare plans and make changes online at Medicare.gov, by phone, or through a local counselor.

What happens if you miss the October 15 important date

If you do not make a change by December 7, you stay in your current plan (or remain without Part D coverage if you are not enrolled). You cannot switch plans again until the next October 15, with one exception: a may have access to event such as loss of employer coverage, moving out of your plan's service area, or a change in your income may open a Special Enrollment Period lasting 60 days from the date of the event.

Missing the important date also triggers a potential late enrollment penalty. If you go without Part D coverage when you are first may be able to access and later join, Medicare adds a permanent surcharge to your premium — roughly 1% of the national average Part D premium for each month you were uninsured. This penalty stays with you for as long as you have Part D coverage.

The exception is if you have creditable coverage (prescription drug coverage as good as or better than Medicare Part D) through an employer, union, or other source. Creditable coverage protects you from the late penalty as long as you enroll in Part D within 63 days of losing that coverage.

How to compare plans during open enrollment

The easiest way to compare Part D plans is through the Medicare Plan Finder tool at Medicare.gov. You enter your current medications, and the tool shows you which plans cover those drugs, what your out-of-pocket costs would be, and the monthly premium for each plan. The tool updates every October with the new year's plan information.

You can also call Medicare directly at 1-800-MEDICARE (1-800-633-4227) to speak with a representative who can walk you through your options. If you prefer in-person help, your State Health Insurance information Program (SHIP) offers free counseling — you can find your local SHIP at shiptalk.org or by calling 1-877-839-2675.

When comparing plans, look beyond the premium. Check the deductible (the amount you pay before the plan starts covering drugs), the copays or coinsurance for your specific medications, and whether your pharmacy is in the plan's network. A plan with a lower premium may cost you more overall if your drugs carry higher copays.

When to enroll in Part D for the first time

If you are turning 65 and enrolling in Medicare for the first time, your initial enrollment period lasts seven months — it begins three months before the month you turn 65 and ends three months after. If your birthday is in June, for example, your initial enrollment period runs from March through September.

If you miss your initial enrollment period and do not have creditable coverage, the late enrollment penalty applies. You can still join Part D during the next October 15 open enrollment, but the penalty will be added to your premium permanently.

If you are already on Medicare but have not yet joined Part D (for example, because you had employer coverage), you have until December 7 of the current open enrollment to join without penalty, provided you enroll within 63 days of losing your creditable coverage.

Changes to your plan's costs and coverage starting January 1

Every January 1, Part D plans adjust their premiums, deductibles, copays, and the list of drugs they cover. A medication you paid $10 for in December may cost $25 in January under the same plan. A drug that was covered last year may move to a higher tier (requiring a higher copay) or be removed from the formulary entirely.

This is why reviewing your plan during October open enrollment matters even if you have been happy with your current coverage. The Medicare Plan Finder tool shows you these changes side by side, so you can see whether staying with your plan or switching makes sense for your specific medications and budget.

If your plan removes a drug you take, you may be able to request a coverage exception or switch plans outside the normal open enrollment window. Contact your plan directly or call Medicare to discuss your options.

How to make changes during open enrollment

You can enroll, switch, or drop a Part D plan in three ways: online at Medicare.gov, by phone at 1-800-MEDICARE, or in person through a local counselor or insurance agent. Online enrollment is usually fastest — you can complete it in 15 to 20 minutes once you have decided which plan you want.

If you are switching plans, you do not need to formally drop your current plan. When your new plan's coverage begins on January 1, your old plan automatically ends. However, if you are dropping Part D coverage entirely (because you have other prescription drug coverage), you should notify your current plan in writing or by phone to avoid being charged a premium you do not need.

Keep a record of the date and method you used to make your change. Medicare sends a confirmation letter in the mail, but having your own record helps if there are questions later.

Special situations: employer coverage, Medicaid, and life changes

If you have prescription drug coverage through a current or former employer, union, or retiree plan, you may not need to join Part D right away. However, if that coverage ends, you have 63 days to join Part D without triggering a late penalty. Mark this important date on your calendar — it is shorter than the standard open enrollment window.

If you are on Medicaid and also may be able to access for Medicare, your state Medicaid program may enroll you in a Part D plan automatically. You can switch plans during open enrollment or request a different plan if your current one does not meet your needs.

If you experience a may have access to life event outside of open enrollment — such as moving to a new state, losing employer coverage, getting married, or having a significant change in income — you may be able to make changes to your Part D plan within 60 days of the event. Contact Medicare or your State Health Insurance information Program to confirm whether your situation qualifies.

Frequently Asked Questions

Can I change Part D plans more than once during open enrollment?

Yes. You can make multiple changes during the October 15 to December 7 window. However, only your final selection takes effect on January 1. If you enroll in Plan A on November 1 and then switch to Plan B on November 20, only Plan B will be active starting January 1.

What if my doctor prescribes a new medication after December 7?

If your current Part D plan does not cover the new drug, you can request a coverage exception from your plan, or you can wait until the next October open enrollment to switch plans. In urgent situations, contact your plan and your doctor — sometimes plans will cover a drug temporarily while an exception request is being reviewed.

Do I have to enroll in Part D if I am still working and have employer coverage?

No, as long as your employer coverage is creditable (as good as or better than Medicare Part D). When you retire or lose that coverage, you have 63 days to join Part D without a late penalty. Check with your employer's benefits office to confirm your coverage is creditable.

Can I drop Part D if I no longer take prescription medications?

Yes, you can drop Part D during open enrollment. However, if you later rejoin, you may owe a late enrollment penalty unless you have creditable coverage from another source. If there is any chance you will need medications in the future, staying enrolled may be cheaper than paying the penalty later.

What if I enroll in a plan but change my mind in January?

Once January 1 arrives, you cannot switch plans until the next October open enrollment unless you have a may have access to event. If you made a mistake during enrollment, contact Medicare when ready — in rare cases, they may allow a correction if you call within a very short window, but this is not may provide.